N

#include <iostream>
#include<iomanip>


using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k;
    double l, v1, v2;
    cin >> n >> l >> v1 >> v2 >> k;
    int blocks = (n + k - 1) / k;
    double t = l / (v1 * blocks + (v2 - v1) / 2);
    double each = (v1 + v2) / 2 * t;
    cout << fixed << setprecision(12);
    cout << (l - each) / v1 + each / v2 << endl;
    return 0;
}